The present disclosure relates to a lighting control system and to a method for generating supply currents for at least two LED channels. Such LED channels may be particularly used for driving segmented LED backlights.
Conventional displays produce white background illumination either by a cold cathode tube, white light-emitting diodes, LEDs, or by a combination of red, green and blue LEDs. Because of their fast turn-on time, backlights with LEDs allow control of the brightness by means of pulse modulation. Such LED backlights will be considered further here.
For subjective increase of contrast, the LED backlighting of a display is typically subdivided into segments, each with its own driving and thus its own brightness control. The task of determining the brightness is conventionally performed by a digital video processor. The segments are conventionally driven by means of pulse modulated signals. However, with the use of conventional pulse modulation techniques, a dynamic range of the desired brightness may be insufficient, in particular in view of backlight systems for 4K or UHD TV sets. For example, the high dynamic range, HDR, specification requires an increased dynamic range for the brightness.